Neoplastic proliferation oflymphoid
cells that forms a mass; may arise in a
lymph node or in extra nodal tissue
Lymphnode
Lymph Node
Development
The lymph sacs are transformed
into groups of lymph nodes in
early fetal life, at about the third
month, except the upper portion
of the cisterna chyli, which
persists.
The mesenchymal
cells will give rise
to the lymph node
capsule and the
connective tissue
framework of the
node.
Lymph Node distribution
Lymph Nodes of the Neck
major site of B and T lymphocytes
Histology of the Thymus
Site of T-cell differentiation and maturation
Located in the anterosuperior mediastinum
Encapsulated
Cortex dense with immature cells
Medulla pale with Mature Tcells and Hassal corpuscles (Reticular cells)